1. Field of the Invention
The present invention relates to floor panels or tiles which form a grid-like floor when laid over a support, such as a subfloor. The floor panels are ideally suited for suspended flooring in industrial structures which are to meet cleanroom specifications such as are required for the production of integrated circuit chips, electronic components and other products which are subject to contamination from airborne particles.
2. Prior Art
The advance of modern technology into the world of miniaturization has necessitated the development of unique manufacturing environments. For example, the preparation of multilayered, integrated computer chips includes the fabrication of wafer masks and layouts that include hundreds of tiny circuits whose operational condition depends upon the absence of foreign materials and very accurate placement of circuit components on the chips. These chips are prepared in an industrial cleanroom which is classified based upon the amount of microcontamination within the room. Examples of such cleanrooms are shown in an earlier U.S. Pat. No. 4,667,579, issued May 26, 1987 and the related art mentioned in that patent.
Grid-like floors have been used in such structures, with the floor comprising panels or tiles which are supported on support posts at tile corners so as to form an air exchange plenum beneath the grid-like floor. These panels or tiles have been cast from such materials as iron, aluminum and composites, and have had a variety of geometric patterns.
The attachment of wall sections and other structures and equipment to such grid-like floor has typically been limited in attachment orientation to the particular geometric pattern of the grid openings. Molly bolt fasteners have been used to expand and couple equipment or structure to the bottom surface of the grid-like floor through such grid openings. Accordingly the position and orientation of the grid openings in the floor panels has been determinative of available positions for attached structures. The inadequacy of current grid-like floor structure to permit unlimited orientation of structures and equipment is further exacerbated by the frequent need to shift equipment position within an existing cleanroom facility. When an optimum rearrangement or modification of a cleanroom fabrication set up is precluded because of incompatible flooring, serious costs and consequences result. These include expensive structural modification to rebuild floor structure and loss profits due to down time.
In addition, the panels of the prior art have not had a symmetrical pattern which allows the tile to be laid in any orientation. Instead, conventional tiles are directional, meaning they must be laid in a specific orientation. Rotation of these tiles by 90.degree. would be unacceptable because of resulting pattern non-uniformity. This limits versatility in floor layout because tile orientation becomes a factor. This non-uniformity in pattern also generates a non-uniform response to air flow distribution. In other words, flow distribution with respect to one orientation of a conventional pattern will not be the same for that pattern when rotated 90.degree..
Other shortcomings in current suspended floor tiles include excessive weight with only limited strength and excessive material leading to high cost. Further, there has been no provision for ready installation of utility boxes, for electrical air or water conduit, through the floor panels. Prior art practice required cutting openings in flooring to develop such service lines. Inasmuch as open space between the floor panels and the subfloor provides an advantageous space for running utilities such as electrical and telephone connections, it would be desirable to provide means for rapidly and easily inserting a utility box in the floor panels to accommodate such utilities.
3. Objectives
A principal objective of the present invention is to provide a novel floor panel or tile which is cast with a grid pattern which forms the upper tread surface of the floor when the panels or tiles are laid, with the open space in the grid pattern being up to 60% or greater, and wherein at least one pair of closely spaced, planar slats extend across the panel. The spacing between the slats is such that a threaded fastener and other fastening means can be engaged between the slats for quick and easy mounting of wall sections, posts, equipment apparatus, and other items to the floor.
Another objective of the present invention is to provide such floor panels or tiles which are symmetrical about their central axes, such that the floor panels or tiles can be laid in any orientation and order, with a consistent, uniform pattern and air flow being achieved for the laid floor.
A still further objective of the present invention is to provide a preformed, removable section in the floor panel which accommodates insertion of a utility box.